Danilo Petrucci is under no illusions that his one-year deal as a factory Ducati rider is a 'once-in-a-lifetime' chance and is determined to make the absolute most of it.

"I'm 28, I have to jump on this train," he said. "I don’t know how many chances I will have in the future so I have to play this chance really well.

"I'm doing all my work very calmly because I know the only thing I have to do is believe.

"Davide [Tardozzi] always said to me, 'you have to believe in yourself' and this makes things change."

Petrucci certainly plenty of reason to believe in himself on Wednesday, when he finished on top of the timesheets for the first time as an official rider during the opening day of the year-ending Jerez test.

The Italian outpaced team-mate and double title runner-up Andrea Dovizioso by 0.217s after 53 laps of the Spanish Grand Prix venue, continuing his strong early impressions of the new GP19 following a close fifth fastest time at Valencia.

"I'm happy. Even if it's only the first day of testing and the classification is not so important, any time you are first means you are the best and you have to pick up the good things!" he smiled.

"The good things are that we are quite fast, even on used tyres. And this is a point I need because I've always been fast on the single lap, but then after a few laps I start to struggle with the rear tyre temperature. I always slide a bit. Things that since Valencia I have no more, I'm quite fast even on used tyre and I'm happy."

But Petrucci is keeping his feet firmly on the ground, reserving final judgement until he tests in the heat of Sepang next February.

"We have to say all this in Sepang, because I struggle a lot when the temperature is warmer and today for sure the air and track temperature is not so hot.

"At the moment everything is working but we always see very good lap times in November in Jerez. Then in May, we will have a new asphalt here, which is a big question mark and especially we will have 50 degrees on the ground which makes things more difficult."

Pressed on where the apparent rear tyre improvement has come from, Petrucci said it's a combination of riding style changes and the new machinery.

"I'm focussing really hard on picking up the bike more quickly and stay calm with the throttle, but for sure the [new] bike helps a little bit," he said.

"But I'm working really hard. Working on this means you are slower so during the race you cannot work on your riding style. It's not a good situation because during a race weekend you always push from FP1 until the last lap of the race.

"So you only see the data, with Dovizioso doing this or Jorge was doing this, but you cannot change your instinct. Here you can work, 'waste' one or two laps to understand things.

"I don’t know if the bike helps me, but for sure it's a step higher compared to the previous one."

The Italian also has plenty of room for improvement, since "we haven’t touched the bike regarding set-up. We've tried many different components, it's always a very long work, but I want to have a good feeling with the same bike in all the circuits. It's a thing I have to improve from the previous year."

Petrucci's rise through the MotoGP ranks has been something of a rags-to-riches tail.

It began on the slowest of CRT machines in 2012 before getting a proper MotoGP prototype at Pramac Ducati in 2015, where Petrucci went on to claim six podiums on ever more competitive machinery before the dream factory team chance for 2019.

"For me it's a once-in-a-lifetime chance and I'm giving my all already," Petrucci said. "For sure the Pramac team was a very good team, I think the best Independent team, but in the factory team you talk with the engineers for the chassis, the engineers for the electronics.

"They give you a lot of information and help you to decide which solution is better. Maybe one time you try a new component and you say 'okay, this is better or not? Because I'm going slower, but I feel better, so which is the right choice?' and they help you more."

One of the most open and entertaining riders to speak with, Petrucci admitted he may have to watch his words a little more carefully in future, "if not Tardozzi and Gigi are ready with the machine gun to shoot me!"